Currently, examples of a medical fluoroscopic imaging apparatus include a CT (Computed Tomography) scanner, an MRI (Magnetic Resonance Imaging) apparatus, a PET (Positron Emission Tomography) apparatus, an ultrasonic diagnostic apparatus, a CT angiography apparatus, an MR angiography apparatus, a vein imaging apparatus, and other apparatuses. When these apparatuses are used, for the purpose of obtaining clear images and the like, a plurality of kinds of drug solutions different in specific gravity or viscosity is injected into the body of a patient. For this purpose, for example, when contrast agent and saline are injected, a drug solution injecting apparatus having two syringes is used.
When the contrast agent and the saline are injected in this manner, a tube is connected to each of the two syringes, and the two tubes are connected via a T-shaped joint. Thus, the contrast agent and the saline are joined together in the joint portion and injected into the patient through an indwelling needle tapped into a blood vessel of the patient. For example, FIG. 2 in Patent Literature 1 discloses a T-shaped joint 45A.